1. Field of the Invention
The present invention relates to a ball-and-socket switch for signalling the selectable inclination directions of a base plane.
2. Description of the Prior Art
Such gravity-dependent switches refer to the force of gravity and characterize the deviation of a base plane from a particular position of this plane with respect to the force of gravity in a certain direction. The particular position of the base plane with respect to the force of gravity is the rest position of the base plane. Ball-and-socket switches of this kind are used to signal the deviation of an object from a given rest or operating position, and they can also be used to produce switching or control commands that depend on a position or a setting. For example, it is known from the German utility model specification DE-898132.3 for such a switch to be incorporated in portable appliances or equipment, especially fan heaters, irons and the like, with a view to monitoring the operating position of the equipment and then cutting off the current supply whenever the appliance assumes a position other than its operating position.
From the French patent application No. 1.504.706, again, there is known a mechanical ball-and-socket switch with several bearing positions of a switching ball that, by means of its weight, will close mechanical switches at each such bearing position. This makes it possible to switch different functions according to the particular position of the ball-and-socket switch. Furthermore, the switching ball is maintained in its switch position in a relatively long tube running in the direction of the force of gravity. When particular control commands have to be set with the ball-and-socket switch of the French patent specification, one has to select particular positions of the ball-and-socket switch that are determined by the external shape of the socket that guides the ball of the ball-and-socket switch.
A ball-and-socket switch has been proposed by the present applicants in DE-Offenlegungsschrift 3924551 and makes it possible to set certain selectable positions of the ball-and-socket switch. Given the particular design of the ball-guiding socket housing of the ball-and-socket switch, the switching ball within the housing can assume only a very limited number of rest or final bearing positions. Intermediate positions are not possible in this socket. This is obtained by means of special guidance elements in the socket housing of this switch and, more precisely, a pyramid-shaped recess in the base plane of the socket housing and a special design of the side walls that rise out of this base plane in the interior of the socket housing. These side walls are so designed that they will not permit the switching ball to come to rest between any two of its final bearing positions and will always deflect it into one of these final bearing positions.